You know, come to think of it, I do recall selling several boxes
of strange and exotic engineering parts to Empoor about a
month ago. I'm not sure what they'd be used for, but I know that
they were delivered to Tuurem.

The box is at 54,30. Coming from Shattrath, you pass 2 huts on your left, one
on your right, then come to a bridge. Cross the river to your left (instead of
going across the bridge). Look in the ruined huts there. You'll know you're
there when you find the Blood Elf Courier.